Is ashwagandha (Withania somnifera) a safe and effective treatment for anxiety in adults with mild to moderate anxiety and no underlying medical conditions?

Ashwagandha for Anxiety

Ashwagandha is not recommended as a treatment for anxiety in adults because it lacks inclusion in evidence-based clinical practice guidelines, has not been adequately studied compared to established first-line treatments (SSRIs/SNRIs), and should not replace proven pharmacological or psychological interventions.

Why Ashwagandha Is Not Guideline-Recommended

The most recent clinical practice guidelines for anxiety disorders do not include ashwagandha among recommended treatments. The Japanese Society of Anxiety and Related Disorders/Japanese Society of Neuropsychopharmacology (2023) explicitly states that alternative agents beyond SSRIs, SNRIs, and cognitive behavioral therapy "have not been adequately studied and are thus not included in the guideline with or without recommendations" 1. This reflects the current medical consensus that herbal supplements lack the rigorous evidence base required for clinical recommendations 2.

What Should Be Used Instead

First-line treatment for anxiety in adults consists of SSRIs (such as sertraline, paroxetine, escitalopram) or SNRIs (such as venlafaxine), which have demonstrated high treatment response rates (NNT = 4.70 for SSRIs, NNT = 4.94 for SNRIs) and safety profiles comparable to placebo 1. These recommendations are based on 26 RCTs for SSRIs and 5 RCTs for SNRIs in adults with anxiety disorders 1.

For moderate to severe anxiety, combining pharmacotherapy with cognitive behavioral therapy (CBT) provides superior outcomes compared to either treatment alone 3, 4. CBT should be structured with approximately 14 individual sessions over 4 months, with each session lasting 60-90 minutes 4.

The Research Evidence on Ashwagandha

While research studies show some promise for ashwagandha, the evidence has significant limitations:

• A 2024 meta-analysis of 9 RCTs (558 patients) found ashwagandha reduced Perceived Stress Scale scores (MD = -4.72), Hamilton Anxiety Scale scores (MD = -2.19), and serum cortisol levels (MD = -2.58) compared to placebo 5.

• A 2022 meta-analysis of 12 RCTs (1,002 participants) demonstrated significant reductions in anxiety (SMD: -1.55) and stress (SMD: -1.75) with ashwagandha supplementation 6.

• However, both meta-analyses identified the certainty of evidence as "low" due to high heterogeneity (I² = 93.8% for anxiety, 83.1% for stress) and methodological limitations 5, 6.

• The most cited individual trial used 300 mg twice daily for 60 days in 64 subjects with chronic stress, showing significant reductions in stress scores and cortisol levels (P<0.0001 and P=0.0006 respectively) 7.

Critical Limitations and Safety Concerns

The research on ashwagandha has not been conducted with the same rigor as pharmaceutical trials for anxiety disorders, lacks long-term safety data, and has not been compared head-to-head against proven first-line treatments 5, 6, 8.

Reported adverse effects include:

• Mild to moderate events: somnolence, epigastric pain/discomfort, loose stools, giddiness, drowsiness, and nausea 8.
• The safety profile with long-term administration remains unclear 5.
• No serious adverse events were reported in the reviewed trials, but the total exposure and follow-up duration remain limited 7, 8.

Clinical Algorithm for Anxiety Treatment

For adults with mild to moderate anxiety:

1. Start with an SSRI (sertraline, escitalopram, or paroxetine) at standard doses, with gradual titration 1, 4.
2. Assess treatment response at 4 weeks and 8 weeks using standardized instruments (GAD-7, HADS, or BAI) 3.
3. If inadequate response by 8 weeks despite good adherence, modify treatment by adding CBT, switching to an SNRI (venlafaxine), or trying an alternative SSRI 3, 4.
4. For severe anxiety, combine pharmacotherapy with CBT from the outset 3.

Common pitfalls to avoid:

• Do not wait beyond 8 weeks to adjust treatment if minimal improvement occurs, as this delays recovery 3.
• Be aware that SSRIs may cause initial increased anxiety or agitation; consider starting with a subtherapeutic "test" dose 4.
• Monitor for discontinuation syndrome, particularly with shorter-acting SSRIs like paroxetine 4.
• Avoid benzodiazepines for long-term use due to abuse potential, dependence risk, and cognitive impairment 3.